1 files changed, 103 insertions, 11 deletions

diff --git a/lib/tsan/rtl/tsan_sync.cc b/lib/tsan/rtl/tsan_sync.cc
index abb5a2ad298f..b25346ef344f 100644
--- a/lib/tsan/rtl/tsan_sync.cc
+++ b/lib/tsan/rtl/tsan_sync.cc
@@ -17,14 +17,17 @@
 
 namespace __tsan {
 
-SyncVar::SyncVar(uptr addr)
+SyncVar::SyncVar(uptr addr, u64 uid)
   : mtx(MutexTypeSyncVar, StatMtxSyncVar)
   , addr(addr)
+  , uid(uid)
   , owner_tid(kInvalidTid)
+  , last_lock()
   , recursion()
   , is_rw()
   , is_recursive()
-  , is_broken() {
+  , is_broken()
+  , is_linker_init() {
 }
 
 SyncTab::Part::Part()
@@ -45,8 +48,61 @@ SyncTab::~SyncTab() {
   }
 }
 
+SyncVar* SyncTab::GetOrCreateAndLock(ThreadState *thr, uptr pc,
+                                     uptr addr, bool write_lock) {
+  return GetAndLock(thr, pc, addr, write_lock, true);
+}
+
+SyncVar* SyncTab::GetIfExistsAndLock(uptr addr, bool write_lock) {
+  return GetAndLock(0, 0, addr, write_lock, false);
+}
+
+SyncVar* SyncTab::Create(ThreadState *thr, uptr pc, uptr addr) {
+  StatInc(thr, StatSyncCreated);
+  void *mem = internal_alloc(MBlockSync, sizeof(SyncVar));
+  const u64 uid = atomic_fetch_add(&uid_gen_, 1, memory_order_relaxed);
+  SyncVar *res = new(mem) SyncVar(addr, uid);
+#ifndef TSAN_GO
+  res->creation_stack.ObtainCurrent(thr, pc);
+#endif
+  return res;
+}
+
 SyncVar* SyncTab::GetAndLock(ThreadState *thr, uptr pc,
-                             uptr addr, bool write_lock) {
+                             uptr addr, bool write_lock, bool create) {
+#ifndef TSAN_GO
+  {  // NOLINT
+    SyncVar *res = GetJavaSync(thr, pc, addr, write_lock, create);
+    if (res)
+      return res;
+  }
+
+  // Here we ask only PrimaryAllocator, because
+  // SecondaryAllocator::PointerIsMine() is slow and we have fallback on
+  // the hashmap anyway.
+  if (PrimaryAllocator::PointerIsMine((void*)addr)) {
+    MBlock *b = user_mblock(thr, (void*)addr);
+    Lock l(&b->mtx);
+    SyncVar *res = 0;
+    for (res = b->head; res; res = res->next) {
+      if (res->addr == addr)
+        break;
+    }
+    if (res == 0) {
+      if (!create)
+        return 0;
+      res = Create(thr, pc, addr);
+      res->next = b->head;
+      b->head = res;
+    }
+    if (write_lock)
+      res->mtx.Lock();
+    else
+      res->mtx.ReadLock();
+    return res;
+  }
+#endif
+
   Part *p = &tab_[PartIdx(addr)];
   {
     ReadLock l(&p->mtx);
@@ -60,6 +116,8 @@ SyncVar* SyncTab::GetAndLock(ThreadState *thr, uptr pc,
       }
     }
   }
+  if (!create)
+    return 0;
   {
     Lock l(&p->mtx);
     SyncVar *res = p->val;
@@ -68,12 +126,7 @@ SyncVar* SyncTab::GetAndLock(ThreadState *thr, uptr pc,
         break;
     }
     if (res == 0) {
-      StatInc(thr, StatSyncCreated);
-      void *mem = internal_alloc(MBlockSync, sizeof(SyncVar));
-      res = new(mem) SyncVar(addr);
-#ifndef TSAN_GO
-      res->creation_stack.ObtainCurrent(thr, pc);
-#endif
+      res = Create(thr, pc, addr);
       res->next = p->val;
       p->val = res;
     }
@@ -86,6 +139,39 @@ SyncVar* SyncTab::GetAndLock(ThreadState *thr, uptr pc,
 }
 
 SyncVar* SyncTab::GetAndRemove(ThreadState *thr, uptr pc, uptr addr) {
+#ifndef TSAN_GO
+  {  // NOLINT
+    SyncVar *res = GetAndRemoveJavaSync(thr, pc, addr);
+    if (res)
+      return res;
+  }
+  if (PrimaryAllocator::PointerIsMine((void*)addr)) {
+    MBlock *b = user_mblock(thr, (void*)addr);
+    SyncVar *res = 0;
+    {
+      Lock l(&b->mtx);
+      SyncVar **prev = &b->head;
+      res = *prev;
+      while (res) {
+        if (res->addr == addr) {
+          if (res->is_linker_init)
+            return 0;
+          *prev = res->next;
+          break;
+        }
+        prev = &res->next;
+        res = *prev;
+      }
+    }
+    if (res) {
+      StatInc(thr, StatSyncDestroyed);
+      res->mtx.Lock();
+      res->mtx.Unlock();
+    }
+    return res;
+  }
+#endif
+
   Part *p = &tab_[PartIdx(addr)];
   SyncVar *res = 0;
   {
@@ -94,6 +180,8 @@ SyncVar* SyncTab::GetAndRemove(ThreadState *thr, uptr pc, uptr addr) {
     res = *prev;
     while (res) {
       if (res->addr == addr) {
+        if (res->is_linker_init)
+          return 0;
         *prev = res->next;
         break;
       }
@@ -179,15 +267,19 @@ void StackTrace::ObtainCurrent(ThreadState *thr, uptr toppc) {
   n_ = thr->shadow_stack_pos - thr->shadow_stack;
   if (n_ + !!toppc == 0)
     return;
+  uptr start = 0;
   if (c_) {
     CHECK_NE(s_, 0);
-    CHECK_LE(n_ + !!toppc, c_);
+    if (n_ + !!toppc > c_) {
+      start = n_ - c_ + !!toppc;
+      n_ = c_ - !!toppc;
+    }
   } else {
     s_ = (uptr*)internal_alloc(MBlockStackTrace,
                                (n_ + !!toppc) * sizeof(s_[0]));
   }
   for (uptr i = 0; i < n_; i++)
-    s_[i] = thr->shadow_stack[i];
+    s_[i] = thr->shadow_stack[start + i];
   if (toppc) {
     s_[n_] = toppc;
     n_++;